The present invention relates to protective covers for mechanical assemblies, and more specifically, to a corrosion inhibiting sprayable thermoplastic cover for bearing assemblies, and the method of making and using this cover.
Industrial operations such as manufacturing lines often come to a screeching halt when mechanisms in the infrastructure malfunction or stop working. These failures are costly, potentially dangerous, and frustrating. Mechanical problems in an industrial operation are particularly troublesome insofar as it isn't usually possible to “swap out” a bad part, so repairs often require shutting down the entire operation.
Corrosion and contamination are leading causes of premature failure in rotating systems such as bearing assemblies. In an effort to prevent these issues, Corrosion Inhibiting Sprayable Thermoplastics (“CISTs”) are used in the industry to protect both stored and operational bearing assemblies.
The conventional delivery method for CISTs is mobilizing spraying equipment and applying the CIST product directly onto the bearing assembly as a hot liquid. Said another way, the spraying equipment is brought to the bearing assembly, and the CIST is applied in situ. This is considered the best procedure because it isn't practical to remove bearing assemblies from industrial operations, treat them, and return them to the underlying structure.
An exemplary device and method of applying CIST in situ is set forth in U.S. Pat. No. 9,211,562 entitled DEVICE AND METHOD FOR MELTING AND SPRAYING THERMOPLASTICS to Boehm et al., which issued on Dec. 15, 2015, and is hereby incorporated in its entirety.
Once the liquefied CIST is cool, it becomes a flexible solid covering over the bearing, creating a barrier to corrosion and contamination entry. The CIST does not bond to the bearing housing or shaft surface, thereby allowing both to function freely underneath the coating. This method is very effective, and the life of protected equipment is increased exponentially. Unfortunately, however, this system has shortcomings.
One problem of applying CIST via mobilized spraying is that installed bearing assemblies are often difficult to access with the application equipment due to length of spray hose, size of application equipment, and/or limited access to surfaces with the spray gun. Another issue is the cost of application equipment. Yet another shortcoming is the significant time that is necessary for application equipment to melt the CIST, which adds to equipment downtime.
As can be seen, there is a need for a protective CIST cover for bearing assemblies that doesn't require mobilized spraying equipment in situ. It is desirable that this cover can be fit onto bearing assemblies that are hard to access. It is also desirable that this cover is relatively inexpensive, easy to use, and easy to transport. It is also desirable that the cover can be fixed relatively quickly, and with standard tools and equipment.